GFR Calculator
Estimate your glomerular filtration rate (eGFR) with the race-free 2021 CKD-EPI creatinine equation, plus the matching CKD stage.
Your details
How to use this calculator
1. Enter age and gender
The 2021 CKD-EPI equation adjusts for age and uses different coefficients for males and females. It does not use race, unlike older versions.
2. Add your serum creatinine
Use the value from a recent blood test. Toggle the unit to match your lab report — mg/dL (common in the US) or µmol/L (common elsewhere). The tool converts µmol/L for you.
3. Read your eGFR and stage
The big number is your estimated GFR in mL/min/1.73 m². Below it you'll see the matching chronic kidney disease (CKD) stage, from G1 down to G5.
4. Discuss it with a clinician
eGFR is a screening estimate, not a diagnosis. A single value can be affected by hydration, muscle mass, and recent diet. Bring questions to your doctor.
About eGFR and CKD stages
What is eGFR and what does it measure?
Estimated glomerular filtration rate (eGFR) approximates how much blood your kidneys filter each minute, reported in mL/min/1.73 m². It is calculated from serum creatinine, age, and gender using the 2021 CKD-EPI equation, which does not use race. Higher numbers generally mean better filtering.
What do the CKD stages mean?
G1 (≥90) normal, G2 (60–89) mildly reduced, G3a (45–59) and G3b (30–44) moderately reduced, G4 (15–29) severely reduced, and G5 (<15) kidney failure. Stages G1 and G2 are only considered CKD when other signs of kidney damage are present.
Can this calculator diagnose kidney disease?
No. This is an estimate for general information only and is not a diagnosis. eGFR must be interpreted by a clinician alongside other tests, your history, and a repeat measurement. Always consult a doctor about your kidney health.